The present disclosure relates to a thin-film transistor (TFT), for example, that uses an oxide semiconductor, and a display unit and an electronic apparatus that use the TFT.
Zinc oxide, oxides containing oxygen and indium, and some other oxides exhibit excellent semiconductor (active layer) properties. In order to apply these oxides to electric devices, such as thin-film transistors (TFTs), light-emitting devices, and transparent conductive films, accordingly, study and development of oxides are being accelerated. It is known that when such oxides are applied to active layers (channels) of TFTs, the TFTs exhibit great electron mobility and superior electrical characteristics, in comparison with TFTs made of amorphous silicon. Moreover, TFTs made of oxides advantageously have the potential for great electron mobility, even when being formed under low temperature conditions, such as at about an ambient temperature.
When a semiconductor device is formed on a substrate made of, for example, silicon (Si) or glass, a silicon nitride film or a silicon oxide film is used as a barrier film that blocks the entry of impurities (e.g., alkali ions) from the substrate to the semiconductor device. For example, Japanese Unexamined Patent Application Publication No. 2012-164873 describes a TFT in which an oxide semiconductor is formed on a surface of a substrate with a barrier film therebetween.